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High Availability (HA) for VMS. The HA mechanism improves VM Availability and automatically starts VMS in the resource pool if a VM is faulty.
If the HA function has been enabled in advanced Settings in a cluster, users can select whether to support the HA function when creating VMS in the cluster. The system periodically checks the VM status. If a VM is faulty, for example, when a physical server is down, the system migrates the VM to another physical server and restarts the VM to ensure rapid vm recovery. Currently, the system can detect causes of VM faults, including physical hardware faults and system software faults.
After a VM is restarted, it boots again and loads the OPERATING system just as a physical machine does. Therefore, the contents that were not saved to the hard disk when a fault occurred are lost.
If the HA function is not enabled for a VM, the VM will be stopped if a fault occurs. Users need to start the VM.
Vm HA working principles:
The VM or physical node is faulty
The VRM node checks the VM status and finds that the VM is faulty
If the VRM VM supports HA, select an available CNA host to start the VM based on the saved VM information, such as specifications and volumes
The CAN node receives an HA request and creates a VM based on VM specifications and volume information
During the startup process, the VM remounts the previous volumes, including user volumes
HA homebrew: Hosts in a cluster elect an active node to monitor the status of each host and maintain a VM list. When a host is faulty, the active node starts VMS running on the faulty host on another host.
